Many if not most light truck type automotive vehicles are provided with trailer hitches to enable the towing of trailers by the truck. In many cases, the vehicle bumper is provided with a hitch mount platform enabling one or more ball type hitches to be mounted directly to the bumper so that the bumper becomes the towing connection between the vehicle structure and the trailer. Of late, especially for use in conjunction with deluxe pickup trucks, rear bumpers are provided which are highly chromed for pleasing appearance. To maintain the pleasing appearance of the rear portion of the vehicle structure, hidden trailer hitches have been provided which are mounted to the frame structure of the vehicle and provide a trailer hitch receiver that is exposed through a license plate opening in the bumper. Thus, when use of the trailer hitch is desired the license plate holder is simply pivoted upwardly or downwardly to an out of the way position and the hitch bar is inserted into the receiver and secured with its retainer pin. When a trailer hitch of this character is installed the receiver is typically fixed centrally of a transverse hitch strut having its extremities bolted or otherwise secured to the vehicle frame. This transverse strut however is located in space that would otherwise be occupied by a full size spare wheel and tire assembly which, in many cases is raised and lowered by a spare tire retainer and lift mechanism that is secured to the vehicle frame beneath the truck. For this reason when a hidden trailer hitch is employed a full size spare wheel and tire assembly can not normally be located beneath the bed of the truck and thus must be transported at another suitable location, such as within the bed of the truck. This is disadvantageous however because spare wheel and tire assemblies carried within the bed of the truck can bounce out of the truck bed and be lost and can be and are readily stolen. Further, if the spare wheel and tire assembly are mounted and locked within the bed of the pickup truck the mounting and locking mechanism is typically expensive and cumbersome and detracts from the pleasing appearance of the vehicle as well as taking up truck bed space. The only spare wheel and tire assembly that can be mounted beneath the truck bed of the vehicle when hidden hitches are employed is a small dimension spare wheel and tire assembly, typically referred to as a "donut" which is only intended for very limited vehicle operation. In cases where large heavy trailers are towed by the vehicle, the use of donut type spare wheel and tire assemblies even for limited vehicle operation can be quite dangerous.
For the purpose of vehicle conversions to provide for the aesthetically pleasing appearance of the rear portion of a light truck vehicle the vehicle bumper is often replaced by a decorative bumper typically referred to as a "roll pan" which may be composed of fiberglas, a polymer material or a metal material. The roll pan is generally intended to be painted with the same color as the vehicle or a color that is pleasing in relation to the color of the vehicle. A roll pan that is frequently used for truck conversions of this nature is typically referred to as the ZR1 roll pan which includes the tail light mounts that replace the tail lights of the truck. This roll pan is of contoured, decorative appearance and defines a central license plate opening. Typically this license plate opening is covered by a pivotally mounted license plate support to which the license plate of the vehicle is secured by means of screws or bolts. Ordinarily, when roll pans are employed to define the rear portion of a vehicle conversion it is not practical to employ a trailer hitch. Obviously this is a significant disadvantage to truck owners who prefer the decorative appearance of a light truck conversion but who also wish to tow trailers such as, boat trailers, horse/cattle trailers, etc. To overcome this disadvantage hidden trailer hitches have been employed that position a trailer hitch receiver in registry with the license plate opening thus permitting the trailer hitch to be exposed to view only when a trailer hitch drawbar is in assembly with the hidden hitch receiver. As mentioned above however the trailer hitch typically occupies a portion of the space that is needed for mounting a full size wheel and tire assembly beneath the bed of the pickup truck. Thus, when trailer hitches of this nature are employed the limited available space permits only a donut type spare wheel and tire assembly to be mounted beneath the pickup bed. If a full size spare wheel and tire assembly is transported, it must be transported in another location such as in the bed of the pickup truck.
It is desirable therefore to provide a hidden, receiver type trailer hitch mechanism which is mounted to the vehicle frame structure in such manner that the receiver is oriented in registry with a central opening of a vehicle bumper or roll pan so that ample space remains beneath the bed of the pickup truck for mounting a full size spare wheel and tire assembly. It is also desirable to provide in combination with the hidden receiver type trailer hitch a spare tire support and lift relocator which reorients a full size spare wheel and tire assembly by moving its support and lift mount forwardly so that the spare tire can be supported beneath the bed of the pickup truck without interfering with the trailer hitch or any other truck structure.
Many trailer hitch devices are adapted for assembly to the frame of a pickup truck of other such vehicle by means of vertical connection flanges of significant length. These hitch connection systems are typically provided with vertical risers which are connected to respective ends of a transverse trailer hitch strut and which are provided with rather small connection flanges that are bolted or otherwise secured to the frame of the vehicle. The vertical risers necessary to position the hitch receiver lower than the truck bumper. These trailer hitch risers and connection flanges, because they define lever arms of significant length, generally can be characterized as the "weak point" of the trailer hitch structure. If significant force is applied to trailer hitches of this type, the hitch risers can yield to the extent that they fail. If this happens, obviously the connection of the trailer hitch with the vehicle can fail and significant damage can result both to the vehicle and the trailer. In some cases, the trailer hitch can be completely torn away from the frame structure of the vehicle so that the vehicle connection with the trailer can become completely separated. It is desirable therefore to provide a hidden, receiver type trailer hitch having a transverse trailer hitch strut with its respective ends bolted or otherwise secured to the frame structure of the vehicle to thus eliminate the weakness that is ordinarily present when riser type trailer hitch/vehicle frame connections are employed.
Another weakness of conventional receiver type trailer hitches is that safety chain receptacles are provided that are typically defined by a transverse safety chain bar having openings at each of its ends or safety chain connectors that are fixed to other portions of the vehicle structure. These safety chain connections are often relatively weak and therefore can be torn away especially if the trailer being towed is of significantly heavy weight. It is therefore desirable to provide a safety chain connection structure that is fixed directly to the main transverse strut of the trailer hitch structure to thereby provide for secure retention of the safety chains in the event the trailer connection with the vehicle should be lost for any reason.